Just to add to the thread, rather than start a new one...
I have a Brother MFC on a network, and I thought I'd see if I could get the scanning features to work. I went to the Brother Center and installed the recommended software. Here is what I found:
The twain driver causes Photoshop to crash when used. It appears to look for a local scanner and can't find it on the LAN.
The brother tools all appear to not work. There is a status monitor that always says the printer is not ready. I think because it can't find the printer.
The control center software appears to launch when I log in, even though it isn't in my startup items. Since installing the software, the fan on my G5 runs at high, regardless of the temperature of the system. After "uninstalling" the software (killing /Libraries/Printers/Brother/Utilities), the fan issue went away.
Now I just have to find the twain plugin and kill it.
In summary, the brother software appears to not help and only hurts if you have a MFC on a LAN.